This report presents the results of an interlaboratory comparison (ILC) which focussed on the determination of total bromine, total sum of polybrominated biphenyls (PBB), total sum of polybrominated diphenylethers (PBDE), brominated diphenylethers (BDE-47, BDE-99, BDE-183 and BDE-209) and decabrominated biphenyl (BB-209) in plastic.
The test material used in this exercise was the Quality Control material (IRMM-310) from the Institute for Reference Materials and Measurements (IRMM) a poly(ethyleneterephthalate) (PET) granulated that has been fortified with commercially available technical mixtures of polybrominated diphenylethers and polybrominated biphenyls. The material was relabelled to avoid its recognition. Twenty-five laboratories from 15 countries registered to the exercise, from which 23 reported results.
The informative values provided by the IRMM-310 material information sheet were taken as the assigned values and their associated uncertainties for all measurands. Studies to asses the adequacy of the selected test material regarding its homogeneity for all the selected measurands were undertaken
Participants were invited to report the uncertainty of their measurements. Laboratory results were rated with z- and ζ-scores (zeta-scores) in accordance with ISO 13528. The standard deviation for proficiency assessment was fixed to 25 % of the respective assigned value by the advisory board of this ILC.
The outcome of the exercise was illustrating quite well the difficulties laboratories do have to provide consistent values for the investigated measurands; the share of satisfactory z-scores ranged between 61 and 88 %. There was a clear tendency to underestimate most of the measurands. The most influencing variables, leading to the observed variability and lack of trueness, were investigated.JRC.DG.D.6-Food Safety and Qualit
